Real estate activities Standard Industrial Classification (SIC) codes of UK-based importers and exporters 68100 - Buying and selling of own real estate (287626) 68201 - Renting and operating of Housing Association real estate (28294) 68202 - Letting and operating of conference and exhibition centres (1784) 68209 - Other letting and operating of own or leased real estate (457215) 68310 - Real estate agencies (49195) 68320 - Management of real estate on a fee or contract basis (135288)